An armoured vehicle is obscured by smoke from a burning barricade during an operation to evict anti-government "red shirt" protesters from their encampment in Bangkok May 19, 2010. Thai troops and armoured vehicles broke through barricades of tyres and staves on Wednesday in a fresh offensive to evict thousands of anti-government protesters from their fortified camp in central Bangkok, witnesses said. REUTERS/Caren Firouz (THAILAND - Tags: POLITICS MILITARY CIVIL UNREST IMAGES OF THE DAY)